Year	US Dollars
1970	435673000
1971	520237000
1972	554353000
1973	631607000
1974	783760000
1975	817833000
1976	941718000
1977	1141625000
1978	1381696000
1979	1562191000
1980	1849034000
1981	2241835000
1982	2632034000
1983	2890238000
1984	2998355000
1985	3544639000
1986	4086689000
1987	4754432000
1988	5209641000
1989	5185722000
1990	5867505000
1991	6580744000
1992	6476091000
1993	6902623000
1994	7960616000
1995	8395502000
1996	8298763000
1997	8106315000
1998	9057341000
1999	9943047000
2000	9249851000
2001	8952127000
2002	10122937000
2003	10726003000
2004	11600417000
2005	11300132000
2006	11853451000
2007	14161317000
2008	16320825000
2009	19504197000
2010	21684211000
2011	25795383000
2012	35735941000
2013	39313859000
2014	42262753000
2015	43925209000
2016	46607902000